There are signs that devices capable of providing an input to a computer or an electronic instrument through a gesture are becoming widespread.
For example, Japanese Patent No. 4031255 discloses an input device that captures an image of a gesture performed by a user within a space with a camera to convert the gesture into an input command. The input device stores a specific gesture and a specific input command and correlates the specific gesture and the specific input command with each other. The input device also includes a unit that recognizes the gesture and a unit that converts the recognized gesture into the input command. Therefore, the user can input any command without directly operating the input device just by performing a gesture operation in front of the electronic instrument.
In the input device that recognizes the gesture, sometimes an input command that varies according to a preference of the user is allocated to a certain gesture. For example, it is assumed that there is a user who wants to allocate an operation to “change a channel of a television set” to a gesture to “move a hand from side to side” and a user who wants to allocate an operation to “change a volume of the television set” to the gesture to “move the hand from side to side”.
In order to deal with this situation, the input device of Japanese Patent No. 4031255 identifies a user who performs a gesture by detecting a face from an image captured by the camera. Therefore, the gesture and the input command can be correlated with each other for each user to perform customization suitable for individual preference.
However, in the input device of Japanese Patent No. 4031255, although a person can be identified by the face, which person performs the detected gesture cannot be correctly recognized in a case that a plurality of faces is taken in the image.
For example, it is assumed that a user A and a user B are present in front of a television set, and that an input device detects a gesture through a camera installed in a front surface of the television set. At this point, in a case that the users A and B allocate different commands to the gesture (for example, the user A allocates “turning up the channel” and the user B allocates “turning up the volume” to the gesture), because the input device cannot identify the user who performs the gesture, the input device cannot decide which command to perform.